cashco P3 Instruction manual

IOM-P3
03/16
SECTION I
I. DESCRIPTION AND SCOPE
The Model P3 is a pressure reducing regulator used to control downstream (outlet or P2 ) pressure. Available in
sizes 1/4" (DN8), 3/8" (DN10) and 1/2" (DN15). The unit is suitable for cylinder gaseous services. Refer to Techni-
cal Bulletin P3-TB for design conditions and selection recommendations.
SECTION II
II. INSTALLATION
MODEL P3
TWO STAGE CYLINDER GAS
PRESSURE REDUCING REGULATOR
1. An inlet block valve should always be installed.
2. If service application is continuous such that
shutdown is not readily accomplished, it is rec-
ommended that an inlet block valve, outlet block
valve, and a manual bypass valve be installed.
3. Pipe unions should be installed to allow removal
from piping.
4. An outlet pressure gauge should be located ap-
proximately ten pipe diameters downstream, and
within sight.
5. All installations should include a downstream re-
lief device if the inlet pressure could exceed the
pressure rating of any downstream equipment or
the maximum outlet pressure rating of the unit.
6. Clean the piping of all foreign material including
chips, welding scale, oil, grease and dirt before
installing the regulator. Strainers are recom-
mended.
7. In placing thread sealant on pipe ends prior to
engagement, ensure that excess material is
CAUTION
Installation of adequate overpressure protection
is recommended to protect the regulator from
overpressure and all downstream equipment
from damage in the event of regulator failure.
removed and not allowed to enter the regulator
upon startup.
8. Flow Direction: Install so the flow direction match-
es the inlet stamp on the main regulator body (1).
9. For best performance, install in well drained hori-
zontal pipe.
10. Basic Regulator - (Refer to Figure 2, Model P3):
Regulator may be rotated around the pipe axis
360°. Recommended position is with 2nd stage
knob (4) vertical upwards.
11. Regulators are not to be buried underground.
12. For insulated piping systems, recommendation is
to not insulate regulator.
Recommended Piping Schematic
For Pressure Reducing Station
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
ISO Registered Company

IOM-P32
SECTION IV
IV. STARTUP
SECTION V
V. SHUTDOWN
SECTION III
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations reg-
ister on the diaphragms (7.1). The registering
pressure is the outlet, P2, or downstream pres-
sure. The range springs (15) oppose movement
of the diaphragms. As outlet pressure drops,
the range springs push the diaphragms down,
opening the ports; as outlet pressure increases,
the diaphragms push up and the ports close.
2. A complete diaphragm failure will cause the regu-
lator to fail open.
The maximum outlet pressure is stamped on the
body as the upper range spring pressure level, and
is the recommended “upper operative limit” for
the sensing diaphragms (see Section IV. Startup,
Step 7). Higher pressures could damage the
diaphragms. (Field hydrostatic tests frequently
destroy diaphragms. DO NOT HYDROSTATIC TEST
THRU AN INSTALLED UNIT; ISOLATE FROM TEST.)
CAUTION
1. Start with the block valves closed. A bypass valve
may be used to maintain outlet pressure in the
downstream system without changing the follow-
ing steps.
2. Relax 2nd stage range spring (15) by turning knob
(4) counter clockwise (CCW) until rotation comes
to a complete stop.
3. If it is a “hot” piping system, and equipped with
a bypass valve, slowly open the bypass valve
to preheat the system piping and to allow slow
expansion of the piping. Closely monitor outlet
(downstream) pressure via gauge to ensure not
over-pressurizing. NOTE: If no bypass valve is
installed, extra caution should be used in starting
up a cold system; i.e. do everything slowly.
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve ob-
serving the outlet (downstream) pressure gauge.
Determine if the regulator is flowing. If not, slowly
rotate knob (4) clockwise (CW) until flow begins.
6. Continue to slowly open the inlet (upstream) block
valve until fully open.
7. Continue to slowly open the outlet (downstream)
block valve, especially when the downstream pip-
ing system isn't pressurized. If the outlet (down-
stream) pressure exceeds the desired pressure,
close the block valve and go to Step 2, then return
to Step 4.
8. When flow is established steady enough that the
outlet (downstream) block valve is fully open,
begin to slowly close the bypass valve if installed.
9. Develop system flow to a level near its expected
normal rate, and reset the regulator set point by
turning knob (4) CW to increase outlet pressure,
or CCW to reduce outlet pressure.
10. Reduce system flow to a minimum level and
observe set point. Outlet pressure will rise from
the set point of Step 9. The maximum rise in
outlet pressure on decreasing flow should not
exceed the stated upper limit of the range spring
by greater than 10%. Example with 2-100 psig
(.14-6.9 Barg) range spring at low flow the outlet
pressure should not exceed 110 psig (7.6 Barg),
if it does, consult factory.
Do not walk away and leave a bypassed
regulator unattended.
CAUTION
1. On systems with a bypass valve, and where sys-
tem pressure is to be maintained as the regulator
is shut down, slowly open the bypass valve while
closing the inlet (upstream) block valve. Fully
close the inlet (upstream) block valve. (When on
bypass, the system pressure must be constantly
observed and manually regulated. Close the
outlet (downstream) block valve.
2. If the regulator and system are to both be shut
down, slowly close the inlet (upstream) block
valve. Close the outlet (downstream) valve only
if regulator removal is required.

IOM-P3 3
SECTION VI
VI. MAINTENANCE
To prevent damage to body, use soft jaws when
placing body in a vise.
5
SPRINGS UNDER COMPRESSION. Prior to
removing spring chambers, relieve range
spring compression by turning 2nd stage knob
(4) CCW until rotation comes to a complete stop.
Failure to do so may result in flying parts that
could cause personal injury.
WARNING
CAUTION
A. General:
1. Maintenance procedures hereinafter are
based upon removal of the regulator unit from
the pipeline where installed.
2. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of
nonreusable parts, i.e. gaskets, etc.
3. Refer to Figure 2 for basic regulator and Fig-
ure 1 for the diaphragm subassembly.
B. 2nd Stage Diaphragm Replacement:
1. Securely install the body (1) in a vise with
knob (4) directed upwards.
2. Relax 2nd stage range spring (15) by turn-
ing knob (4) CCW until rotation comes to a
complete stop. NOTE: It is not necessary
to remove knob (4) before removing spring
chamber (6) from the body (1).
3. Remove the spring chamber (6) by grasping
the flats and turning CCW. NOTE: Upon
removal, the range spring (15), range spring
clip (16), and spring button (5) should remain
inside the spring chamber.
4. Remove 2nd stage diaphragm subassembly
(7) consisting of the actuator nut (7.3), dia-
phragm (7.1), actuator post (7.2), actuator
gasket (7.4), actuator o-ring (7.5). Remove
diaphragm gasket (10).
C. 1st Stage Diaphragm Replacement:
1. Invert the body and securely install in a vise
with acron nut (4) directed upwards.
2. Rotate nut CCW and remove. Measure the
height of the exposed adjusting screw and
record that value here. ___________.
3. Relax 1st stage range spring (15) by turn-
ing adjusting screw (2) CCW until spring
compression is released. NOTE: It is not
necessary to remove adjusting screw before
removing the spring chamber (6) from the
body (1).
4. Remove the spring chamber (6) by grasping
the flats and turning CCW. NOTE: Upon
removal, the range spring (15), range spring
clip (16), and spring button (5) should remain
inside the spring chamber.
5. Remove 1st stage diaphragm subassembly
(7) consisting of the actuator nut (7.3), dia-
phragm (7.1), actuator post (7.2), actuator
gasket (7.4), actuator o-ring (7.5). Remove
diaphragm gasket (10).
NOTE: The following Steps 6 thru 9 apply to
both the first and second stage diaphragm
subassemblies (7).
6. Remove actuator nut (7.3) and separate all
parts of the diaphragm subassembly (7,).
7. Clean body (1) diaphragm flange surfaces
and all reusable parts according to owner's
procedures. Do not scratch diaphragm
gasket seating surface. NOTE: On regu-
lators originally supplied as “oxygen clean”,
Option-M, maintenance must include a level
of cleanliness equal to Cashco cleaning stan-
dard #S-1134. Contact factory for details.
Figure 1: Diaphragm Subassembly
WARNING
SYSTEM UNDER PRESSURE. Prior to performing
any maintenance, isolate the regulator from the
system and relieve all pressure. Failure to do so
could result in personal injury.

IOM-P34
8. Inspect and replace any necessary parts.
NOTE: Use only parts manufactured and
supplied by Cashco, Inc. for these products.
See Section VIII.
9. Reassemble diaphragm subassembly (7) by
placing the actuator gasket (7.4), diaphragm
(7.1), and actuator o-ring (7.5) over the
threads of the actuator post (7.2). NOTE: Use
the thickest of the two diaphragms (7.1) for
1st Stage diaphragm subassembly (7). Place
a thread sealant compound on the threads of
the actuator post (7.2) prior to installing the
actuator nut (7.3). Install actuator nut (7.3)
and tighten to the following torque value: 15
Ft-lbs (20 Nm).
10. Place the 1st stage diaphragm gasket (10)
onto the body (1) diaphragm flange area.
Place 1st stage diaphragm subassembly (7)
on top of the gasket (10).
11. Lubricate the threads of the body (1) with
a lightweight grease that is compatible with
service use. Rotate the spring chamber (6)
CW by hand onto the threaded portion of
the body (1) until firmly seated against the
diaphragm gasket (10). Tighten to the follow-
ing torque value: 65–70 Ft lbs (88–95 Nm).
12. Recalling height value of C.2, rotate adjust-
ing screw (2) CW to compress spring (15) to
factory established pressure set point. Hand
tighten acron nut (4) on adjusting screw (2).
12. Invert the body (1). Repeat Steps 9 thru 11
for 2nd stage diaphragm subassembly (7).
13. Pressurize with air and spray liquid leak de-
tector around body (1) and spring chambers
(6) to test for leakage. Ensure that an outlet
pressure is maintained during this leak test
of at least mid-range spring level; i.e. 2-100
psig (.14-6.9 Barg) range spring, 51 psig
(3.5 Barg) test pressure minimum.
D. Trim (Seat) Replacement:
1. Remove spring chamber subassemblies and
diaphragm subassemblies per Section VI.
Steps B and C.
2. Remove seat retainers (13) by rotating seat
CCW.
3. Remove poppets (8) and poppet springs (9).
4. Clean debris from within the body (1) cavity.
Clean all parts to be reused according to
owner's procedures.
NOTE: On regulators originally supplied as “oxy-
gen clean”, Option-M, maintenance must in-
clude a level of cleanliness equal to Cashco's
cleaning standard #S-1134. Contact factory
for details.
5. Inspect all parts for damage and replace if
necessary. NOTE: Use only parts manufac-
tured and supplied by Cashco, Inc. for these
products. See Section VIII.
6. Place the 1st stage poppet spring (9) into
body (1) cavity.
7. Place poppet (8) inside the poppet spring
(9). NOTE: The angled seating surface of
the poppet (8) must face up toward the seat
(12).
8. Install new seat retainer (13) with seat (12)
into body (1) cavity with the seat facing down-
ward toward the angled seating surface of the
poppet (8). Tighten seat retainer (13) to the
following torque value: 12 – 15 Ft-lbs (16 – 20
Nm).
9. Reinstall the 1st stage diaphragm subassem-
bly (7) and spring chamber subassembly(2)
per Section VI, Steps B and C.
10. Invert the body (1) and repeat Steps 6 thru 9
for the 2nd stage reassembly.
11. Bench test unit for suitable operation. NOTE:
Regulators are not tight shutoff devices.
Even if pressure builds up beyond set point,
a regulator may or may not develop bubble
tight shutoff.
12. Pressurize with air and spray liquid leak de-
tector around body (1) and spring chambers
(2.1) to test for leakage. Ensure that an outlet
pressure is maintained during this leak test
of at least mid-range spring level; i.e. 2-100
psig (.14-6.9 Barg) range spring, 51 psig
(3.5 Barg) test pressure minimum.

IOM-P3 5
SECTION VII
VII. TROUBLE SHOOTING GUIDE
1. Erratic operation; chattering.
Possible Causes Remedies
A. Oversized regulator; inadequate rangeability. A1. Check actual flow conditions, re-size regulator for minimum and
maximum flow.
A2. Increase flow rate.
A3. Decrease regulator pressure drop; decrease inlet pressure by
placing a throttling orifice in inlet piping union.
A4. Install next step higher range spring.
A5. Before replacing regulator, contact factory.
B. Worn poppet; inadequate guiding. B. Replace trim ( possible body replacement).
C. Weakened/broken poppet spring. C. Replace poppet spring. Determine if corrosion is causing the
failure.
2. Regulator can't pass sufficient flow.
Possible Causes Remedies
A. Regulator undersized. A1. Confirm by opening bypass valve together with regulator.
A2. Check actual flow conditions, re-size regulator; if regulator has
inadequate capacity, replace with larger unit.
B. Incorrect range spring (adjusting aluminum knob CW does not
raise pressure to proper level).
B. Replace range spring with proper higher range.
C. Too much droop. C1. Review droop expected.
C2. Contact factory.
3. Sluggish operation.
Possible Causes Remedies
A. Fluid too viscous. A. Heat fluid. Contact factory.
4. Excessive pressure downstream.
Possible Causes Remedies
A. Regulator not closing tightly. A. Inspect the seating. Clean and lap metal seat surfaces; replace
if lapping does not remedy. If composition seats are depressed,
nicked or embedded with debris, replace trim.
B. Downstream block. B. Check system; isolate (block) flow at regulator inlet - not outlet.
Relocate regulator if necessary.
C. No pressure relief protection. C. Install safety relief valve, or rupture disc.
D. Restricted diaphragm movement. D. Ensure no moisture in spring chamber at temperatures below
freeze point.

IOM-P36
SECTION VIII
NEW REPLACEMENT UNIT:
Contact your local Cashco, Inc., Sales Represen-
tative with the Serial Number and Product code.
With this information they can provide a quotation
for a new unit including a complete description,
price and availability.
–7–
VIII. ORDERING INFORMATION
NEW REPLACEMENT UNIT vs PARTS "KIT" FOR FIELD REPAIR
To obtain a quotation or place an order, please retrieve the Serial Number and Product Code that was stamped on
the metal name plate and attached to the unit. This information can also be found on the Bill of Material ("BOM"),
a parts list that was provided when unit was originally shipped. (Serial Number typically 6 digits). Product Code
typical format as follows: (last digit is alpha character that reflects revision level for the product).
PARTS "KIT" for FIELD REPAIR:
Contact your local Cashco, Inc., Sales Represen-
tative with the Serial Number and Product code.
Identify the parts and the quantity required to repair
the unit from the "BOM" sheet that was provided
when unit was originally shipped.
NOTE: Those part numbers that have a quantity indicated
under "Spare Parts" in column "A” reflect minimum
parts required for inspection and rebuild, - "Soft
Goods Kit". Those in column “B” include minimum
trim replacement parts needed plus those "Soft
Goods" parts from column "A".
If the "BOM" is not available, refer to the cross-
sectional drawings included in this manual for part
identification and selection.
A Local Sales Representative will provide quotation
for appropriate Kit Number, Price and Availability.
CAUTION
Do not attempt to alter the original construction
of any unit without assistance and approval from
the factory. All purposed changes will require a
new name plate with appropriate ratings and new
product code to accommodate the recommended
part(s) changes.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be
construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right to
modify or improve the designs or specifications of such product at any time without notice.
Cashco, Inc. does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any
Cashco, Inc. product remains solely with the purchaser.

IOM-P3 7
Figure 2:
Repair Parts
Item No. Description Kit B
1 Body
2 Adjusting Screw
3 Knob Nut
4 Knob 2nd stage / Acron nut 1st stage
5 Spring Button
6 Spring Chamber
7 Diaphragm Subassembly
7.1 Diaphragm ------------------------‡‡
7.2 Actuator Post
7.3 Actuator Nut
7.4 Actuator Gasket -----------------‡‡
7.5 Actuator O-ring ------------------‡‡
8 Poppet --------------------------------- ‡‡
9 Poppet Spring ----------------------- ‡‡
10 Diaphragm Gasket ----------------- ‡‡
12 Seat ------------------------------------ ‡‡
13 Seat Retainer ------------------------ ‡‡
15 Range Spring *
16 Spring Clip
21 Inline Filter---------------------------- ‡‡
39 Snap in cover
‡‡ Recommended Spare Part
1st Stage
2nd Stage
* 2nd stage pressure spring with range 5 to 500 psig,
uses stack of Belleville washers in place of 1st stage
spring.

Cashco, Inc.
P.O. Box 6
Ellsworth, KS 67439-0006
PH [phone]
Fax. # [phone]
www.cashco.com
email: [email protected]
Printed in U.S.A. P3-IOM
Cashco do Brasil, Ltda.
Al.Venus, 340
Indaiatuba - Sao Paulo, Brazil
PH [phone]
Fax. No.
www.cashco.com
email: [email protected]
Cashco GmbH
Handwerkerstrasse 15
15366 Hoppegarten, Germany
PH [phone]
Fax. No. [phone]
www.cashco.com
email: [email protected]